The present invention relates generally to blast and ballistic shielding and more particularly to energy absorbing armor shielding for existing structures and vehicles, as well as personnel, which provides protection especially from projectiles with and without the effects of a blast.
Due to increased threats and awareness of potential terrorist activities, increased attention is being given to protecting structures of all types against damage from projectiles, fire, explosion, and other threats, malicious and accidental. Exposed structural elements of buildings and transportation infrastructure are particularly vulnerable targets for terrorist activity. Thus, there is a need for projectile-resistant and blast and/or ballistic impact shielding for use in both existing and new construction for vehicles and exposed structures.
Ballistic threats do not remain the same over time. Military organizations, terrorists and insurgents are always looking for more aggressive means of destroying armaments. Earlier generations of weapons such as poison arrows, slingshots, single shot muskets, and single shot rifles have morphed into modern multiple shot automatic weapons, armor piercing incendiary bullets, improvised explosive devices and explosively formed penetrators. It is not uncommon today for armor piercing bullets or other metal fragments resulting from an improvised explosive device or explosive formed penetrators to perforate heavy armor consisting of steel, various metal alloys and composite assemblies.
In this regard, the use of ballistic and blast resistant panels or barriers are well known and take on a variety of configurations for providing protection to buildings, vehicles, ships, airplanes and a variety of other applications where armor or other protection is required. It has become increasingly more important to incorporate effective shielding features and systems in vehicles and building structures. Specifically, the goal of armoring modern vehicles is to increase the functionality of armor defeat mechanisms yet reduce the heavy armament which makes vehicles less maneuverable while consuming large amounts of fuel during transport. Moreover, it is important to protect existing building structures and retrofit vehicles which are still vulnerable.
Conventional armor, which may be provided for existing structures or vehicles, is typically solid metallic armor made of steel, aluminum, titanium and alloys thereof. Such solid metallic armor typically possesses significant stopping power to a blast or ballistic threat. However, the steel and aluminum metallic armor has several drawbacks, including low weight efficiency compared to other available systems, such as composite systems. Titanium systems, on the other hand, typically perform better than steel and aluminum, but titanium is extremely expensive and may be cost prohibitive for many applications.
Recently, various improvements on traditional armor have been proposed. For example, commonly owned US Patent Application Publication No. 2005/0144900 A1, published Jul. 7, 2005 to Hallissy et al. discloses blast resistant prefabricated wall panels that contain at least one panel consisting of two structural boards having a thermoset resin-impregnated fiber reinforcing layer there between and extending from sides of the panel. The extension is wrapped at least partially around metal sole and top plates of a metal sole plate, top plate, and stud construction. The panels are capable of resisting explosive blasts without forming secondary projectiles, and are preferably attached to a building structure by energy absorbing deformable brackets.
Also, commonly owned U.S. patent application Ser. No. 11/499,101 by Hallissy et al. discloses a shield for shielding a structural member from an explosive blast or accidental or malicious destruction. The shield includes a plurality of shield members which include cast ultra high strength concrete, wherein the shield members are capable of being assembled to enclose at least a portion of the structural member to provide protection to the enclosed portion from, for example, an explosive blast. In one embodiment, the shield members include a chassis, at least one ballistic liner disposed on the energy absorbing layer, and a concrete-integrating structure.
Accordingly, it would be desirable to provide a shielding system for existing structures and vehicles that is relatively inexpensive and has acceptable weight efficiency. It would be further desirable to provide such a system which can be easily incorporated in or on existing structural elements or vehicles and which can protect such structural elements or vehicles against damage from projectiles and/or explosive devices, both in terms of the energy created by the projectile and its explosion per se as well as from flying objects/debris created during explosive blasts.